Request for review: 7102776 Pack instanceKlass boolean fields into single u1 field

[Jiangli Zhou]

Hi Bob,

Sorry for the delay. Here is the updated webrev with dependencies.cpp fixed: http://cr.openjdk.java.net/~bobv/7102776/webrev.01/. Thanks for catching that!

Thanks,
Jiangli


On 11/09/2011 02:13 PM, Bob Vandette wrote:
> Jiangli,
>
> src/share/vm/code/dependencies.cpp:1636     instanceKlass::cast(d)->set_is_marked_dependent();
>
> Isn't this supposed to be clear_is_marked_dependent()?
>
> Bob.
>
>
> On Nov 9, 2011, at 12:47 PM, Jiangli Zhou wrote:
>
>> Compact following 4 instanceKlass boolean fields into a signal u1 field. Each flag now uses 1-bit. The new field is placed after the _idnum_allocated_count field to utilize the unused 2-byte after _idnum_allocated_count. Compacting these fields saves 4-bytes for each loaded classes.
>>
>>   bool _is_marked_dependent; // used for marking during flushing and
>>   deoptimization
>>   bool _rewritten; // methods rewritten.
>>   bool _has_nonstatic_fields; // for sizing with UseCompressedOops
>>   bool _should_verify_class; // allow caching of preverification
>>
>> http://cr.openjdk.java.net/~bobv/7102776/webrev.00/
>>
>> Tested with runThese on ubuntu. Ran JPRT.
>>
>> Thanks,
>> Jiangli